A well known and effective system for preventing shoplifting comprises a pair of scanners for setting up a microwave field at, for example, an exit of a store. Attached to merchandise to be protected are special tags which carry reradiating circuitry. When an item is properly purchased, the clerk removes the tag at the point of sale. If the tag is not removed and someone attempts to shoplift the tagged item, the reradiator energizes an alarm when it enters the microwave field, thereby alerting store personnel.
The foregoing system has proved to be extremely successful in combating shoplifting. However, certain types of merchandise cannot readily be tagged in such a manner. Tape cassettes, for example, are particularly attractive to shoplifters and are difficult to tag. Furthermore, most stores would prefer to display tape cassettes openly as an encouragement to impulse buying. Many other items present similar problems, such as, for example, small cameras, wrist watches, writing implements, lighters, etc.
Accordingly, it is a primary object of the present invention to provide improved protection for items difficult to tag with reradiating devices. Other objects are to provide such protection while keeping the protected item in open view, and rendering the reradiating device difficult of removal by a shoplifter but easily removable by a checkout clerk. The manner in which these objectives are achieved will be apparent from the following description and appended claims.